Re: [patch 2/2] Implement gdbarch hook user_register_name on ARM

[Yao Qi <yao@codesourcery.com>]

[-- Attachment #1: Type: text/plain, Size: 1617 bytes --]

On 12/23/2010 06:02 AM, Ulrich Weigand wrote:
> Yao Qi wrote:
> 
>> Good catch! set_gdbarch_deprecated_fp_regnum is called in
>> arm_gdbarch_init since 2003, introduced by this patch "Deprecate
>> TARGET_READ_FP, read_fp and FP_REGNUM"
>> http://sourceware.org/ml/gdb-patches/2003-04/msg00471.html
>>
>> set_gdbarch_deprecated_fp_regnum is no longer used in most of targets,
>> and I don't see any reason why we have to keep it in ARM, so I draft
>> this one-line patch.
> 
> Huh, I didn't even see this, I was refering to this line:
>   { "fp", 11 },
> in arm_register_aliases.  As long as this line is there, changes to
> set_gdbarch_deprecated_fp_regnum probably don't matter as this isn't
> even evaluated, since "fp" is just treated as a user register instead
> of a standard register.
> 
Ulrich,
changes to set_gdbarch_deprecated_fp_regnum matters here.

There are two "fp", "pc" and "sp" in user registers.  The first one is
added from builtin_user_regs (fp, pc, sp, ps) in user_regs_init, and the
second one is added from `arm_register_aliases' in our case.  The first
one is always used, so these three in arm_register_aliases are redundant.

  { "fp", 11 },
  { "sp", 13 },
  { "pc", 15 },

How about this patch to remove them?

> But you're right that you need to remove the set_gdbarch_deprecated_fp_regnum
> *also* in order to get the full default logic I had described.
> 

Regression test is done.  Two failures are fixed.
FAIL: gdb.mi/mi-var-display.exp: create variable a2 in different scope
FAIL: gdb.mi/mi2-var-display.exp: create variable a2 in different scope

Committed.

-- 
Yao (齐尧)

[-- Attachment #2: remove_arm_sp_fp_pc_alias.patch --]
[-- Type: text/x-patch, Size: 530 bytes --]

2010-12-23  Yao Qi  <yao@codesourcery.com>

	arm-tdep.c: (arm_register_aliases): Remove sp, pc, and fp

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index 636c1de..11c75cd 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -175,12 +175,9 @@ static const struct
   { "tr", 9 },
   /* Special names.  */
   { "ip", 12 },
-  { "sp", 13 },
   { "lr", 14 },
-  { "pc", 15 },
   /* Names used by GCC (not listed in the ARM EABI).  */
   { "sl", 10 },
-  { "fp", 11 },
   /* A special name from the older ATPCS.  */
   { "wr", 7 },
 };